Blaster engine trouble

Hey guys, I have a 96 blaster that I just had built but a shop by me. Been using him for a year now with all my 2 strokes and he is very good. Put a phone call in about my problem and said hed get back to me but figured I would get you guys' opinion

Motor is 701 with big bore, Coffman pipe, triton head, dual carb, custom water box, welded crank, 190psi compression etc etc.

Just got the ski back and it was running flawlessly, very rich but that was intended for the break in. Have about 10 hours so far after I got it back

This past Sunday I was riding and at the end of my ride randomly the ski wouldn't get up and go, it was bogging but not a carb issue

It would seem very loaded up, when I would blip the throttle it would start clearing out, if I held the throttle half way it would be bogging but trying to clear out almost like and exhaust leak. It was trying to fire (Bum...bum bum...bum bum bum...bum bum) my best description of the sound and feel it was doing

So I had to bring it back anyway for a retourqe and carb adjustment, after I got it back he said I blew a head gasket, one piston black one piston shiny

Figured that was the problem, so I get the ski back and take it out last night, starts going somewhat fine

Start ripping around but after a few mins when I would try a hard lean over turn or power slide it didn't have the power, it was like 3/4 power.

Everytime it did this, BUT when I got into the no wake zone it started doing the same thing It did before I brought it back to him.

So I assumed maybe a needle and seat was stuck open and flooding it out, which would explain the no power at full throttle turns because I had a heavy load on it

Exiting the no wake zone back to the ramp and I try and clear it out, get it up on plane and it wouldn't go full throttle, I keep letting off and going full again until I finally get full throttle

NOW when I would let off and pin the throttle it was fine, but as soon as I went to idle and tried full throttle again it did the same thing like it was loading up

The guy thinks it's electrical, possibly a coil going bad

Personally to me it felt like it was dumping fuel in and could keep up at full throttle but couldn't clear out anything below that

Any suggestions on what you guys might think that sounds like??
 
Check your airlines and make certain of no leaks. Also test the check valve on the fuel tank and make certain it's installed the correct way. Any leak will starve the carb.
 
Checked one way valve on tank and its working properly, also as far as I can see the fuel lines are all in good shape

Can't tell if it's electrical or not, I have been throwing the ski all around since I got it back
 
Just talked to the guy, he said it's the coil

It's cutting in and out so I guess we'll have to wait and see what happens when I get the new one

And he lowered my compression to 150 so it's not like I blew the motor from running 93 with 190psi

Although I'm having him bump it back up to 180
 
I had the exact same issue with one of my blasters. Would rip for a little bit and then if I jumped or even randomly, it would act like it was loaded up and I couldn't get it to Rev. Sometimes it would clear up, sometimes it didn't. I used the same electronics on another engine of mine and it never had any issue. Ended up being a broken reed! Might be something to check...
 
Thanks swl I'm definitely going to look into it, I'm glad I'm not the only one that had this problem

It did the exact same thing to me before my build when I had a broken water box, would only clear out when I got speed so fresh air was getting in

Definitely going to look at the reeds
 
Location
Austin
Have a similar issue, not to hijack but in hard turns mine bogs down and I'll have to feather the throttle a little while going straight to get it to rev up. Its probably about 10-15% of normal throttle response.

Does this on a full tank, thought it might be getting starved. Throttle cable seems to be pulling just fine/equally when I checked it.
 
Location
Austin
Turns out it's a broken Reed Incase anyone was curious

How did you eliminate the possibility of carbs being the issue? What I've researched the diaphragm seems to be my issue, I'm planning on rebuilding but I'm curious if you or anyone else has a simple test to eliminate that possibility. I know we have different issues but they seemed similar enough.
 
Location
Austin
Well I was convinced it was a needle stuck open flooding the carbs out but swl said he had almost the same problem and his was a reed so I pulled carbs but saw the reed broken


Cause any engine damage? What you decide to replace with? Metal/plastic/carbon fiber
 
As far as I know it didn't do any engine damage, I ran the thing three times with it broken, kept hoping the problem was fixed, but always ran good at first and have 205 compression still

Probably going fiber reeds, gonna order Monday morning and see what I should go with

Any suggestions?
 
To recap it wasn't the reeds even though he found a broken one

The jug had a crack in it, previous owner used jb weld to fix it and I guess after the motor build and extra power and vibration it finally let loose

Guy said he filled jug with water and it was dripping onto the crankcase with just gravity, replaced both jigs to be safe

Going to test ride and get back
 
Location
Australia
Had similar issue last weekend after a full rebuild. If you pinned the throttle out of the water and looked down the darbs there was plenty of fuel. Just pulsing after 3k rpm So I figured it was electrical. Checked the ebox I had a bad earth to one of the cd wires (black). Fixed and perfect straight to limiter.
 
To recap it wasn't the reeds even though he found a broken one

The jug had a crack in it, previous owner used jb weld to fix it and I guess after the motor build and extra power and vibration it finally let loose

Guy said he filled jug with water and it was dripping onto the crankcase with just gravity, replaced both jigs to be safe

Going to test ride and get back

Sorry - not to be a di(k but you paid a shop to build/install/test/tune a 701 for you & they did not see a JB weld rigged backyard fix on the jugs? Methinks they owe you a bit of a credit on this one, how much time and $ do you have into chasing this?!?!
Bring that thing down to OC & I can introduce you to a couple of great guys that do amazing work....
Although I shouldn't say too much, my '96 B1 is still shrinkwrapped & winterized, has not seen water since last summer - hope you get it sorted, they are a blast!!
LB
 
Sorry - not to be a di(k but you paid a shop to build/install/test/tune a 701 for you & they did not see a JB weld rigged backyard fix on the jugs? Methinks they owe you a bit of a credit on this one, how much time and $ do you have into chasing this?!?!
Bring that thing down to OC & I can introduce you to a couple of great guys that do amazing work....
Although I shouldn't say too much, my '96 B1 is still shrinkwrapped & winterized, has not seen water since last summer - hope you get it sorted, they are a blast!!
LB
No money cause I'm not paying him for any of this, but after I got the ski back at the end of June, rode for about 10 hours (3 days worth) and it started

Been back to his shop at least 4 times, so pretty much I bought a blaster, had water box issues, gave it to a shop to do a full extreme build, and still havent had a good day riding and it's now September

But I ride until late November so I have time, but I'm ready to go pull it out of there and bring it somewhere else
 
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